THE AMERICAN ENTOMOLOGIST. 



103 



FUNGUS DISEASES OF INSECTS. 



Prof. Elias Metschnikoff gives, in the 

 Zoologischer Anzeiger, No. 47, p. 44-47, a 

 short abstract of his investigations on the 

 fungus diseases of insects during the year 

 1878, together with some more recent ob- 

 servations on the practical application of 

 parasitic fungi for the destruction of in- 

 jurious species. The original contribution 

 is in the Russian language, " On the dis- 

 eases of the larva of the Grain-beetle." 

 (Odessa, 1878.) This beetle is a Lamel- 

 licorn, (AiiisopHa austriaca) which, with 

 several allied species of the same genus, 

 is most injurious to wheat and other grains 

 in Southern Russia. Prof. M. found 

 that the Anisoplia-\ax\a. which lives in the 

 ground is subject to several diseases, one 

 which he calls the "green muscardine," 

 being produced by a parasitic fungus 

 {Isaria destructor). The same fungus was 

 also found to so greatly infest another 

 beetle, Cleoniis punctirentn's, which is very 

 injurious to beets, that in the month of 

 August, when the disease had not yet dis- 

 appeared, about 40 per cent, of the pro- 

 geny of the beetle was destroyed. Of the 

 experiments made to infest the Anisoplia- 

 larva: witli the spores of the Isaria several 

 were successful, but in some cases the larvae 

 remained healthy for a long time. The 

 same experiments made to infest the 

 C/eo/ius-\a.Tvsi were eminently successful. 

 Of 90 larvae which for a short time were 

 brought in contact with the spores. 62 died 

 from muscardine within 12 days. On the 

 imago of the Cleoims the muscardine acts 

 somewhat more slowly but just as surely. 

 Of 58 beetles whicli he infected when fresh 

 from the pupa, 52 died from muscardine 

 within 15 days. From these and other 

 experiments Prof. M. concludes that Isaria 

 destructor produces an epizootic disease, 

 on the insects mentioned, and believes it 

 possible to produce this disease by sowing 

 the spores. But in order to do this it be- 

 comes necessary to cultivate a quantity of 

 the spores. This was easily done by bury- 

 ing insects that had died from muscardine 

 in wet sand and keeping them there for a few 



weeks, when a rich mycelium was found to 

 be developed. It proved much more 

 difficult to cultivate the spores in organic 

 fluid, but finally it was found that when 

 beer mash is kept boiling for some time, 

 and, when cooled, spores are sown on the 

 fluid, a rich mycelium is developed on the 

 surface as well as within the fluid. " The 

 data here given," Prof. M. concludes, " are 

 based upon the principles of the more 

 recent mycology, especially on the classic 

 works of deBary on insecticide fungi, while 

 Hagen relies for his proposed method on 

 the older ideas of Bail, according to whom 

 the parasitic fungi are in genetic relation- 

 ship with the yeast-fungus, moulds and 

 SaprolegnicB. It is on this last supposition 

 that Prof. Hagen thinks it possible that 

 the yeast-fungus when applied to insects 

 can penetrate within the body, live there 

 parasitically as Empusa, and finally cause 

 the death of the host. So long, however, as 

 the scientific basis of this theory is not more 

 firmly established, a practical application of 

 the same is simply out of the question." 



There are over 200,000 species of insects 

 in this country, many of them useful as para- 

 sites and many injurious. Many injurious 

 insects can be held in check by a concert of 

 action. The curculio has been whipped 

 and the coddling moth has been held in 

 check by a concert of action. If the exec- 

 utive committee of our society would offer 

 a premium of $50 or $100 to that township 

 or neighborhood that will bandage and 

 perfectly protect the trees in the largest 

 area, it will be a great credit to the society, 

 and will be the means of doing great good, 

 and as Entomologist of the society I re- 

 commend it. — Prof. A. J. Cook, before the 



Michigan Pomological Society. 



•*—* 



Messrs. List & Franke, booksellers, 

 Leipzig, Germany, offer for sale the rich 

 entomological library of the eminent dip- 

 terist, Prof. Loew, who died a year ago. 



Among European entomologists few were 

 better known in this country than Dr. Jean- 

 Baptiste Alphonse Dechauffour de Bois- 

 duval, who died last December, in his 

 seventy-ninth year. 



